Its more common name is “lie detector,” from the assumption that such bodily functions change measurably when a person gives false answers to questions.

The reliability of results from such tests has been debated since the introduction of polygraphs in the 1920s, and there are numerous restrictions on the use of such results in American courts.

I had an encounter with one of these devices when I was much younger. I was not impressed with its accuracy — apparently it indicated I wasn’t being truthful, but I was. Honest. I think it had more to do with how badly the test session was conducted. Fortunately, it all worked out for me anyway.

This “lie,” by the way, is not the one that I’ve been writing about, the one that many people confuse with “lay.” This “lie,” which is about making false statements, is a regular verb. And that means it has “normal” inflectional forms.

For example:

Present tense: “I lie, you lie, we all lie, everyone lies.”

Past tense: “The congressman lied about those photos.”

Past participle: “You have lied to me for the last time, you villainous viper!”

Present participle: “She has been lying for so many years, she’s really good at it now.”

If only the other “lie” could be so simple. But it isn’t, because it’s an irregular verb.

Present tense: “I lie down every afternoon for a nap” — “lie,” NOT “lay.”

“A semi lies in the ditch along southbound I-39” — “lies,” NOT “lays,” as, unfortunately, it appeared in this newspaper earlier this week.

Past tense: “The body lay there for two days before anyone noticed it” — “lay,” NOT “laid.”

Past participle: “You have lain there all day — it’s time to get up and do something” — “lain,” NOT “laid.”